A High-Temperature Blackbody Radiation Source

Abstract

Abstract : A high-temperature blackbody radiation source, consisting of an electrically heated graphite tube with a small centrally located hole through one wall, was developed for use as a secondary standard in the calibration of radiometric and spectrometric instruments. The spectral emissivity of this source, at 0.65 microns, was calculated by the DeVos method, for which graphite emissivities and temperature gradients were measured in situ with an optical pyrometer. The values of source emissivity ranged from 0.9981 = 0.0004 at 1000C to 0.9997 = 0.0002 at 2000C.